First, sometimes the wrong people come to power anyway. If they can't do it by blatant misinformation and propaganda, they'll do it by "wolf in sheep's clothing" tactics. Once they get power, the machinery is there, just waiting for them to use it to enforce their narrative. Sure, by protecting the narratives that are allowed, you might make it more difficult for such a one to come to power, and therefore less probable. You can't make it impossible, though. And if the thought of such machinery in Orban's hands (or Trump's) doesn't terrify you, you're not thinking.

Second, power changes people. You might be a perfectly fine, democracy-loving person. Give you that kind of power and you might not be the same person forever. As Elrond said, "I fear to take the ring to guard it. I will not take the ring to wield it" - and for very good reason. Too much power is a danger even to the good.

I can't help but to smile the smile of mild horror that calls to overreaching and overzealous censorship of wrongthink ( hate is sufficiently innocuous and broad to cover just about any kind of wrongthink - just the fact that it has been accepted by mainstream as a good enough reason is horrifying ) is so common that is used with adjectives like ruthlessly without any feel for the irony.

I can certainly feel the hate.

And many people rightly saw that the prosperity that happened during Lula's time was because of booming commodities market and exports booming, not because anything he did in particular.

Brazillians voted for Bolsonaro not because he is right wing, but because he promised he would end corruption, and the workers party IS corrupt.

Now that Bolsonaro has proven that he won't end corruption either (starting with him protecting his son), I doubt he will be re-elected, instead whoever else promises to end corruption and is not corrupted that has a good shot.

(1) If you believe that hate-based disinformation campaigns routinely unseat good people ... I might suggest that normalising ruthless deplatforming of "fringe elements" is a strategic blunder?

There is a stereotype of ye goode olde Nazi/Communist regimes. It involves tropes of ruthlessness and deplatforming of fringe elements.

(2) I'm not sure dismissing political opponents as "far right" and "fringe" when they are winning elections is rhetorically feasible. It is hard to get away from the fact that winning an election involves convincing swing voters that a plan is acceptable. It is worth asking some what? and why? style questions. Then getting to answers that don't involve the public becoming suddenly and unexpectedly susceptible to hypnosis.